Pulse wave analysis is used in the measurement of a pulse wave analysis index such as pulse wave velocity. Pulse wave velocity is utilized in medical practice as an index for non-invasively evaluating vein hardness.
The following are examples of techniques for precisely measuring a pulse wave analysis index.
JP 2006-247221A (Patent Literature 1) discloses that a determination as to whether a pulse wave includes noise is made using an autocorrelation function waveform.
JP 2001-128946A (Patent Literature 2) discloses the detection of notches and the calculation of a pulse wave velocity based on a time difference between such notches in order to measure accurate pulse wave velocity information.
JP H10-328150A (Patent Literature 3) discloses the calculation of a pulse wave velocity using the line with the largest slope and the base line of a heartbeat synchronized wave in order to highly precisely measure a pulse wave velocity.
JP 2008-168073A (Patent Literature 4) discloses the detection of a feature point of an acquired pulse wave and the display of a pulse waveform on a screen in real-time with the feature point being clearly indicated, in order to improve reliability and efficiency in arterial sclerosis evaluation.